You know the old joke..."Time flies like an arrow, fruit flies like a banana."
I have found them floating in my airlocks...dead but nonetheless carrying beer-infecting baddies.
As some added protection to your brew (or at least a little more peace of mind), slip a women's ankle-length hose (aka "nylons") over your air lock; pull it down to the neck of the carboy and rubber band it into place.
A pair of hose in a nice nude shade should look smashing this time of year...